A lot of web apps these days involve images. Twitter, Gravatar, Facebook, you name it. For avatars, sharing photos, or whatever, user-submitted images are a big part of the modern web.
Now, suppose you’re building a web app, and you want to allow a user to upload an image of a certain size or aspect ratio (for whatever your purpose is). Now you can’t guarantee that the user will upload an image of the correct dimensions, and you probably don’t want them breaking your layout by submitting a 1200-pixel-wide image. What do you do?
Provide means for the image to be cropped in-browser. There’s a cool little jQuery plugin called Jcrop that allows users to crop images in browser. It seems customizable enough, letting you re-style the selection box, contstain it to a specific aspect ratio, etc. It works fairly similar to Gravatar’s cropping tool.
